Most pharmaceutical substances, such as Epinephrine, Diazepam, and Naloxone, are temperature sensitive. For example, many drugs are required by their manufacturers to be maintained at room temperature (59-86 degrees Fahrenheit). The drugs be maintained within a predetermined temperature range in order to prevent alteration of the drugs.
In buildings such as hospitals or pharmacies, maintaining the temperature of drugs within the required range is relatively simple. Heating, ventilation and air conditioning (HVAC) systems provide a stable room temperature environment inside of the building. Some drugs, known as "refrigerated drugs", are required to be kept at refrigerated (or chilled) temperatures. These drugs can be stocked inside of a suitable refrigerator located inside of the building. However, removing refrigerated drugs from a hospital or pharmacy to an ambulance or other remote location typically exposes the drugs to temperatures outside of the required ranges.
If a drug is maintained outside of its required temperature range for an extended period of time, the drug could be altered in such a way so as to lose its efficacy. Thus, the drug could be administered in a life-threatening situation, only to impede the administration of proper health care due to a misplaced reliance on the effectiveness of the drug. Even worse, temperature effects on the drug could make the drug toxic to a human being.
There exists in the prior art devices for storing drugs within a temperature control environment. Such devices are portable so as to be carded about on ambulances and alike. One such prior art device is described in U.S. Pat. No. 5,217,064. One of the inventors of this application is a co-inventor of U.S. Pat. No. 5,217,064.
It is desired to improve on the prior art devices in general, and specifically on the device described in U.S. Pat. No. 5,217,064. One such improvement is the recording and reporting of instances whenever a drug is exposed to a temperature outside of its required temperature range, when the drug is carried in a portable temperature controlled carrier device. Such a reporting and recording capability is intended to improve the safety and effectiveness of the drugs.
Still another improvement involves maintaining an accountability of the drugs and the administration thereof. Under the prior art, once a drug leaves a pharmacy in a carrier device, circumstances concerning the drug (for example, temperature history, possession and control) are loosely monitored. It is desirable to monitor the administration and disposition of a drug once it leaves the pharmacy in a portable carrier device.
Another consideration in the design of a portable carrier apparatus for pharmaceuticals is the limited energy supply available for maintaining the temperature of the pharmaceuticals. For this reason, it is desirable to temporarily cease efforts in controlling temperature of the pharmaceuticals whenever the carrier is opened to the outside environment. This prevents the unnecessary loss of energy to the outside environment. Many pharmaceuticals are in liquid form. Thus, they have some thermal storage capacity. In other words, when the carrier is open and the pharmaceuticals located inside are exposed to temperatures exceeding their range, the pharmaceuticals will not be instantly compromised, due to the fact that some finite time is required for the liquid pharmaceuticals to exchange energy to the outside environment. It is desirable to measure this thermal storage capacity of pharmaceuticals and utilize such a measurement in regulating the temperature of the pharmaceuticals in order to conserve the energy supply on the carrier.